Assent vs consent

In legal English, consent and assent are often used interchangeably. There is a subtle difference though.
The term assent connotes a positive and voluntary agreement both as a noun and a verb.
“Assent to a proposal of marriage.”
The term consent is neutral in connotation and can apply even when the agreement is given reluctantly.
“The employee consented to the non-compete clause being included in her employment agreement.”